Mechanical time fuse



1948. I E. J. FIX 2,450,890

MECHANICAL TIME FUSE Filed Jan. 23, 1939 Eu ELT'LE l Fix E1 WZ 'W J Altar y5 Patented Oct. 12, 1948 MECHANICAL TIME FUSE Eugene J. Fix, Philadelphia, Pa, assignor to the Government of the United States of America as represented by the Secretary of War Application January 23, 1939, Serial No. 252,417

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 O. G. 757) Claims.

The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates in general to a mechanical time fuse and more particularly it has reference to a safety device for preventing functioning of the firing mechanism until the lapse of a predetermined time from the starting of the clockwork mechanism.

In the type of fuse in which a driven timing disk may be individually adjusted to predispose a peripheral slot with respect to a releasing device for a firing mechanism, it is customary to associate with the setting mechanism, a spring had mer which is operable on setback to provide for starting of the timing disk under control of the clockwork.

The purpose of this invention is to provide means on the hammer for masking the peripheral slot of the timing disk and to prevent the releas ing device from entering the slot until sufiicient time has elapsed for the projectile to leave the bore of the gun.

The specific nature of the invention as well as other objects and advantages thereof will clearly appear from a description of a preferred embodiment as shown in the accompanying drawings in which:

Fig. 1 is a longitudinal sectional view, with parts in elevation, through a portion of a mechanical time fuse showing the parts in the normal position prior to firing;

Fig. 2 is a sectional view on the line 2-2 of Fig. 1, and

Fig. 3 is a fragmentary view showing the parts in a diiferent position.

Referring to the drawings by characters of reference there is shown a portion of a fuse casing including a body 5 and a cap 6 arranged for relative rotational movement. A timing unit, such as a clockwork mechanism, represented at l is housed within the casing and associated with the body so as to be movable therewith. The clockwork mechanism includes a conventional timing disk 8 which is arranged to be driven in rotation by the clockwork and is adapted to be displaced independently of the driving mechanism to position a slot '9 with respect to a finger I0 on the releasing member I I of a firing mechanism.

The timing disk is formed with an offset leaf l2 having a slot or notch l3 which receives a setting pin it fixed in the cap 6. This engagement, which is conventional, provides for independently displacing the timing disk upon relative rotation of the body and cap.

The starting of the timing disk can occur only when the leaf is disengaged from the pin M and this is accomplished by means of a spring hammer i5. The hammer which is anchored to the cap by pins or screws l6 has its free end normally in engagement with the cap due to its inherent resiliency. The free end is customarily rovided with weights lli'l to increase its inertia and thus facilitate its deflection under influence of the force of setback when a projectile equipped with the fuse is fired from a gun. The hammer upon being thus actuated moves the leaf clear of the pin and thereby permits starting of the timing disk.

On the anchored end of the hammer l5 there is formed an apron 18 which overlies and extends to the margin of the timing disk so that it may be in position to mask the slot 9 and to oppose entry of the finger l0 into the slot.

With the parts in the position of adjustment shown in Fig. 2 the timing disk is held against rotation by the setting pin I4 and the finger I!) is prevented from entering the slot 9 by the apron 18. Assuming that the leaf l2 becomes disengaged from the pin 14 under action of the hammer 15, the timing disk could be rotated but whenever its slot 9 is opposite the finger It] the apron will prevent entry of the finger.

Assume now that the cap 6 has been turned to set the timing disk as shown in Fig. 3. On firing, the hammer disengages the leaf from the setting pin and the timing disk commences to rotate under control of the clockwork. The rate of rotation of the timing disk determines the time that is required to elapse before the slot 9 is opposite the finger l0, which, being no longer opposed. by the apron, is free to enter the slot and initiate actuation of the firing mechanism of the fuse. Because of this construction and arrangement the fuse can only function beyond a minimum time setting which insures sufficient time for the projectile to leave the bore of the gun. This time is, of course, that required for disk 8 to rotate to move its slot 9 from its central or initial osition with respect to apron l8, as shown upon Fig. 3, to a position in which said slot is substantially clear of the apron. In short the apron positively establishes a non-firing zone for a time that may be varied to meet particular safety requirements by proper correlation of the arcuate 0r angular extent of the apron with the known rate of rotation of disk 8.

I claim:

1. In a fuse, a casing comprising relatively rotatable parts, a clockwork carried-by one of said parts and including an independently adjustable timing disk adapted to be driven by the clockwork and releasably secured to rotate with the other of said parts, said disk having a peripheral slot, a movable member carried by said one part and adapted to enter the slot of the disk to thereby initiate detonation of the fuse, a setback member fixed to the other part of the casing and arranged to be moved with the timing disk during its independent adjustment, said member having an apron normally masking the slot of the disk and extending over the margin of the disk to thereby normally prevent movement of said member into said slot.

2. In a fuse, a casing comprising relatively rotatable first and second parts, a clockwork carried by said first part and including an independently adjustable timing disk adapted to be driven by the clockwork, said disk having a peripheral slot, a movable member carried by said first part and adapted to enter said slot to thereby initiate detonation of said fuse, a member responsive to acceleration and carried by said second part of the casing, a connection between said second part and disk and releasable by said member on acceleration, said member having an apron normally masking the slot of the disk.

3. In a fuse, a casing comprising a body and a cap interconnected for relative rotation about a first axis, a clockwork carried by said body and including a disk rotatable on an axis parallel to said first axis and having a slot in its periphery, a member carried by said body and adapted to move into said slot, in one rotative position of said disk, to initiate detonation of said fuse, a releasable connection between said disk and said cap whereby the two are held in predetermined rotative relation and normally rotate in synchronism about their respective axes, means responsive to acceleration of said fuse along said axis to release said connection, and an apron carried by said cap in position to mask said slot and prevent movement of said member thereinto when said disk and cap are in said predetermined relation only.

4. A fuse comprising a body and a cap connected for relative rotation, a clockwork carried by said body, a rotatable disc having a notch in its periphery, a slip-friction driving connection between said clockwork and disk, a disconnectable driving coupling between said cap and disk whereby said disk and cap are normally maintained in one position of relative rotation, a member carried by said body and movable into said notch to initiate detonation of said fuse when said disk is in one rotative position relatively to said body, means operable to disconnect said coupling in response to acceleration of said fuse, and an apron fixed to said cap and operative to positively prevent said member from movement into said notch when said cap and disk are in said one position of relative rotation only.

5. A fuse comprising a body and a cap connected for relative rotation, a clockwork carried by said body, a rotatable disc having a notch in its periphery, a slip-friction driving connection between said clockwork and disk, a disconnectable driving coupling between said cap and disk whereby said disk and cap are normally maintained in one position of relative rotation, a member carried by said body and movable into said notch to initiate detonation of said fuse when said disk is in one rotative position relatively to said body, means operable to disconnect said coupling in response to acceleration of said fuse, and an apron fixed to said cap and operative to positively prevent said member from movement into said notch when said cap and disk are in said one position of relative rotation only, said disconnecting means comprising a leaf spring fixed at one end to said cap and having said one end bent to form said apron.

EUGENE J. FIX.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,693,516 Junghans Nov. 28, 1928 1,927,746 Junghans Sept. 19, 1933 2,149,469 Schenk Mar. '7, 1939 FOREIGN PATENTS Number Country Date 414,191 France June 13, 1900 

